Circuit arrangement for carrier current telephone supply sources



Nov. 15, 1938. PQSCHWEIMER 2,136,639

CIRCUIT ARRANGEMENT FOR CARRIER CURRENT TELEPHONE SUPPLY SOURCES Filed Nov. 9, 1956 2 Sheets-Sheet l INVENTOR Kuisw SCHWEIMER BY 9 v ,01 4

ATTORNEY NOV. 15, 1938. p SCHWEIMER R 2,136,639

CIRCUIT ARRANGEMENT FOR CARRIER CURRENT TELEPHONE SUPPLY SOURCES Filed Nov. 9 1936 2 Sheets-Sheet 2 I I i 3% i/PL/Wi 5/ S $3 $4 ILF. m RAD/0 APPARATUS 5 RELAY i pw i] w 2 C E-w z 1 IF E RELAY N PG V V W 220 VOLT A 6 LINE INV EN TOR.

KLAl/S PETER SCHWEIMER ATTORNEY.

Patented Nov. 15, 1938 UNITED STATES CIRCUIT ARRANGEMENT FOR CARRIER CURRENT TELEPHONE SUPPLY SOURCES Klaus Peter Schweimer, Berlin-Grunewald, Germany, assignor to Allgemeine Elektricitats Gesellschaft, Berlin, Germany, a corporation of Germany Application November 9, 1936, Serial No. 109,872 In Germany November 25, 1935 7 Claims.

This invention relates to an improved carrier current telephone supply source.

The object of this invention is to provide an emergency, auxiliary source for wired radio apparatus which is particularly intended for the supply of carrier-current telephony along power lines. The invention essentially consists of a pilot relay designed to test the level of the line potential at certain intervals, which is re-connected under the same magnetic condition with the power system in which the relay operates in the presence of normal voltage on the line. Additional supervisory relays are provided for the purpose of checking up on the voltage condition of the station storage battery acting as an auxiliary or emergency source, and of the converter or inverted rectifier.

It is known from the prior art to operate highfrequency telephony equipment from the mains, that is to say, all of the currents required for the feed of the tubes and the relays are taken from the alternating current line; it is also known in the art to provide auxiliary or emergency sources of supply so that such auxiliary source of current is automatically connected whenever the line voltage happens to fall below a definite pre-arranged level. However, certain difficulties arise in the operation of these schemes in practice. Some of the trouble consists in that a state of potential is liable to arise in which the automatic switching relay just happens to be energized by a potential being at one time slightly above, and at another time somewhat below the level where the change-over occurs, with the result that the relay is caused to operate all the time. This not only means very rapid wear and tear of the relay contacts, but also unfavorable action upon the auxiliary source of supply, the installation to be so fed, and the switching means used therefor.

Now, according to the invention the said drawbacks are avoided by that, after the change-over relay has been caused to respond, preferably after the release of the relay energized from the line voltage, the high-frequency communication apparatus or other mains-supplied apparatus is fed from the auxiliary source of supply for a prearranged adjustable interval of time. Arrangements with this end in view are preferably so made that, after the release of the relay with supervisory action, the auxiliary source of supply is connected only when the source of direct current to energize the same, such as the station or storage battery, is ready for operation and service. Moreover, it is preferable to cause connection of the auxiliary source of supply as a function of the response of the voltage supervisory relay only when a distinct relay serving to supervise the voltage of the auxiliary source of supply has also been caused to respond, After the relay supervising the line voltage has been actually released, the said relay, by way of a change-over contact, is immediately thereafter connected again with a source of potential and maintained in energized condition so that, when the clockwork reconnects the supervisory relay with the line voltage, this operation is brought about in the presence of energization. In other words, in each supervisory action the relay is called upon to merely ascertain whether by chance the voltage has fallen below the limit and level which it requires to keep its keeper or armature in a state of attraction.

One exemplified embodiment of the invention is illustrated by way of example in. Fig. 1 of the annexed drawings schematically and Fig. 2 shows a diagram of the time delay and auxiliary relay portion of the invention. Fig. 3 shows a com plete circuit diagram with the relays and their corresponding contacts in line.

Referring to the drawings, HF is the radio frequency appaartus, say, a radio frequency transmitter and receiver equipment for a radiofrequency telephony along lines (wired radio) more particularly over power lines, remote-control, tele-mechanical, telemeter'ing and similar circuits. In lieu of the radio frequency apparatus there could be connected also some other current-consuming device which is to be supplied with voltage under conditions as permanently as possible, with this condition that for service reasons the potential so supplied should never fall below the normal feeding level. The radio frequency apparatus HF is united with the supply line by way of the relay contacts 53 and .94, for

example, a supply line working with alternating current of 220 v. It will be understood that the type of construction of the radio frequency equipment is immaterial in the present connection; for this reason such details as the lines serving for signal transmission and communication etc. have been omitted in the drawings. Also connected with the alternating current line N is a transformer T in whose secondary circuit is connected in series with a relay Pw by way of the back contact of a change-over contact a2, a rectifier G or a rectifier circuit arrangement, and a resistance W. E denotes an emergency or auxiliary source of supply, such as a storage battery mounted in a power station wherein the equipment for wired radio is installed. The voltage of the said storage battery E is supervised by the aid of a distinct relay Pg. GW indicates a motor generator, an inverted converter or rectifier. The voltage of this converter device is checked up by the agency of a separate relay S. In Fig. 2 relays U, V denote auxiliary relays, Zt is a clockwork, and M shown in Fig. l is a tripping relay.

Now, the operation of the above-mentioned arrangement is as follows:

Suppose the voltage of the alternating current supply line N drops a certain amount sufiicient to cause the direct current relay Pw included in the secondary circuit of the transformer T to be released. The consequence is that the relay Pw closes its back contact pw. If the voltage of the storage battery has been adequately high, the relay Pg has responded and keeps also its contact pg closed. The converter GW, as a result, is started and generates an alternating current voltage. A short while after connection of the converter GW the relay S connected in parallel thereto will be caused to respond and operate, closing its contacts sl, s2 and s5 and changing over its makeand-break contacts 33 and $4 to make connection to converter GW. The radio frequency apparatus HF will then be fed from the station battery by way of the converter GW and the contacts 83 and 34. At the contact s2 is made a response circuit for the relay U so that when the relay Zt has not yet responded, and relay M at contact vi and contact pm is disconnected from the supply current source. Relay U responds, makes its contact ul with the result that relay V is caused to operate, the latter, in turn, closing its contact 212. At the contact 1.52, the relay Pw supervising the line voltage has been connected to the works potential, with the result that the same has a chance to become re-energized. But previously by way of the contact 35, contact 712, contact m, the back contact 3320 had been bridged, with the result that also the shifting over of the contact M and the renewed responding of the relay Pw occasioned thereby will be unable to lead to the disconnection of the converter GW.

After a certain interval of time the response time-lag relay Zt, after expiration of lag of a mechanical or thermal time measuring means optionally attached thereto, is caused to respond and to break at its contacts at the response circuit for relay U. As a result, the said relay U is caused to open its contact ul and it connects at its contact 2L2, while in back position, the energized relay Pro with the transformer T and thus the power line N. During the brief length of time it takes contact u to shift, the field in the relay Pw is maintained, so that the relay is again merely called upon to determine whether the power line will furnish sufficient potential in order that it may keep connected therewith.

After the relay U, by opening of contact at has been released again and as a result also the relay V, and after relay Pw has been caused to respond again, relay M is caused to respond, that is, from minus by way of contacts pw, 1L3 and contact 21! to plus. Relay M is provided with a slight timelag response; it responds after a certain while, and it breaks at its contacts m the holding circuit for the relay S and the circuit of the converter GW so that the latter is disconnected again.

If, however, after the relay Pw had been reconnected with the power line, it was released again, the consequence would have been that the converter GW would not have been disconnected because in this instance relay M would have been unable to fully respond, so that the feed circuit for the converter GW would have been preserved.

A state of non-operativeness of the storage or station supply source E is brought preferably to the attention of the supervising personnel in the station by that some alarm device such as a bell L which is actuated by the aid of the contact pg serving as a voltage supervisor relay for the station battery, whenever the voltage of the latter has dropped below a pro-arranged level. The bell L could also be directly operated from a contact of relay Pg so that the response thereof would be independent of the release of relay Pw.

What is claimed is:

1. A circuit arrangement of auxiliary supply sources for wired radio apparatus normally connected to a main supply line, comprising an auxiliary source of voltage, a main line relay which serves to supervise and test the line voltage, means for causing said main line relay to respond when the line voltage has dropped below, or has exceeded, a certain level, said means comprising a time delay mechanism cooperating with a plurality of contacts to repeat the test at definite time intervals, and provides re-connection to the supply-line voltage which will be effected only when the voltage-supervisory relay has stayed a certain length of time in a state corresponding to the normal main line voltage.

2. An arrangement according to claim 1, with this characteristic feature that the relay supervising the line potential is always re-connected to the power line when the relay windings are in a magnetic condition which corresponds to the normal state of line voltage.

3. An arrangement according to claim 1, with this characteristic feature that the relay supervising the power line potential, after it has been caused to release, is connected with an auxiliary voltage, and that it is re-connected with the power line in attracted state.

4. An arrangement according to claim 1, with this characteristic feature that the auxiliary source of current is subjected to supervisory action from a distinct relay, a current converter device being connected so as to be made a function of the said relay, after release of the relay supervising the power-line potential.

5. An arrangement according to claim 1, with this characteristic feature that the voltage state of the converter, is supervised by a further relay, and that the emergency source of current is connected With the apparatus to be fed only when the converter has reached the proper operating state.

6. A circuit arrangement for auxiliary supply source of apparatus normally connected to a main line' supply source, comprising a main line relay coupled to said main line supply source, an auxiliary battery supply source, a second relay connected to said auxiliary supply source and said main line relay, a time delay relay cooperating with a plurality of contacts to provide a reconnection to said main line supply after said auxiliary supply has been connected to said apparatus for a predetermined time providing said main supply has again obtained its normal line voltage.

7. A circuit arrangement for auxiliary supply source of apparatus normally connected to a main line supply source, comprising a main line relay coupled to said main line supply source, an auxiliary battery supply source, a rectifier, a second relay connected to said auxiliary supply soiuce, said rectifier and said main line relay, a time delay relay cooperating with a plurality of contacts to provide a reconnection to said main line supply after said auxiliary supply has been connected to said apparatus for a predetermined time providing said main supply has again obtained its normal line voltage.

KLAUS PETER SCHWEIMER. 

